Rack-mounted network attached storage (NAS) devices are employed by enterprises for various storage needs.
Equipment designed for rack-mounts typically have a height of that is standardized as multiples of 1.75 inches (44.45 mm) or one rack unit or U and 19-inches (482.6 mm) wide. Typically, a piece of equipment being installed has a front panel height 1/32 inch (0.031 inches or 0.787 millimeters) less than the allotted number of U's. Thus, a 1U rack-mounted computer is usually 1.719 inches (43.7 mm) tall. This allows a bit of room above and below an installed piece of equipment so it may be removed without binding on the adjacent equipment.
A rack-mounted configuration can be used for network-attached storage, for example, in a data center. The rack-mounted configuration enables the NAS device to be mounted within a standard rack that is common in most data centers. However, as noted above, the form factor for a rack-mounted, especially a 1U rack-mounted, has a limited height and space.
A riser card plugs in to the motherboard and provides additional slots for adapter cards, such as SATA interface. Riser cards are common in rack-mounted systems to allow the addition of feature cards in a horizontal position (instead of a standard vertical position). Unfortunately, the features of riser card 114s are generally limited.